Polar CS300 vs. S725x

Hi guys

My trusty (and old) Polar Sport Tester (year 1991 ) is obviously losing its breath, and I guess it's time for me to think about something new.
At the moment, I'm looking at CS300 or S725x. Price difference is quite big between those two (200eur vs. 360eur), but if S725 is much better working one, I don't have problem paying more.
My conditions for HRM are following. It has to be wrist watch, not cycle meter, since I use it more for xc skiing and running then for cycling (I don't care about footpod for running, so that's not an issue). On the other side, I would like to get rid of my Sigma BC1600 cycle meter and use just Polar for bike. This means it would be great, if Polar would have (kinda) same features as my current Sigma BC1600.
I saw S725x has bunch of fancy features, which would come extremely handy few years ago when I was still in competitive xc skiing, but nowadays I don't need any features like interval planning etc. I just do sport for fun nowadays, and interval training is not really fun part of sport, so...
One of my concerns is reliability of CS300. My wife's RS200, which if I understand right, is somehow same line of products just that it's for running, is far from my current Sport Tester's reliability. It works ok, but needs reset every now and then, while I never had single issue with Sport Tester in these 17 years. So how would CS300 and S725 compare in this?
Did anyone ever consider those two models and how did you decide?

I've used the cs300 for 2 years. I had to send it back to polar last summer when water got in it while swimming. Polar promptly replaced the entire watch. I have heard of issues with the wearlink transmitter. I usually wash it after each use. The old t31 was more reliable but not near as comfortable as the wearlink. I'll take that trade off because in cold weather the old style transmitter would never stay in place. I have had no problem with the wearlink so far. I believe both units you are looking at come with the wearlink.

The only problem I've had with the cs300 was interference from passenger train crossings in the Philadelphia area. The unit would reset when I road over certain railroad tracks. I have not gone over tracks with the new watch. I plan routes around them now so I don't loose my data. I would like to try it to see if it was an isloated problem with my old watch or could be something with the entire line. I have had no other resetting or any other problems with the unit

I didn't need all of the features of the 725. I do use it for other sports/exercises and have been extremely happy with my choice. I have handle bar mounts and speed sensors on both my road and mountain bikes.

Polar customer service is great so you should be happy with either choice

I have a 625x and a CS600. The 625x is very similar to the 725x, but has a foot pod instead of speed sensor. The 725x has a barometer so it measures temperature and elevation. When you download the exercise it shows the elevation as profile of the hill. Also I just looked here: http://www.universalcycles.com/ and the 725x is US $271 - 15%(using vip15 coupon) so this is ~160 eur. They may not ship international - just FYI.

I have the CS300 and use it for running and at the gym, but haven't been able to use the bicycle features because I can't get the magnet and pick-up set properly. I installed it on my mt bike front fork and can't even get it close to the 4 mm requirement (front fork on mt bike is considerably bulkier and has more clearance between fork and spokes than road bike).
If your getting it to use as a bike computer on a mt bike you might want to consider this.
Anyone else have this problem, any solutions.